Ok, this is a problem that has plagued me for a long time. I've posted on here before to try to ask to see if there's a solution but no-one could help me.

It just so happens that I managed to figure out the solution myself.

The Problem - MIDI sounded bad and off-key all the time under Windows Vista. This made RPG Maker Games and any others that use Microsoft Wavetable Synth almost unplayable.

The solution? - Get a copy of the gm.dls from Windows XP and put it in your drivers folder within system32. No need to restart.

I'm only posting this so that someone else with the same problem who is searching google may stumble on this and have similar joy.

-Ed